Durable deformation of keratin-containing fibers is conventionally carried out in that the fibers are deformed mechanically and the deformation is set by suitable aids. The fibers are treated with a keratin-reducing preparation before and/or after this shaping. After a rinsing process, the fibers are then treated in the “setting step” with an oxidizing agent preparation and rinsed and the deformation aids (for example curlers or foam rollers) are removed after or during the setting step. If a mercaptan, for example ammonium thioglycolate, is used as the keratin-reducing component, this breaks down some of the disulfide bridges of the keratin molecule into —SH groups, such that the keratin fibers are softened. In the case of subsequent oxidative setting, disulfide bridges are relinked in the hair keratin, such that the keratin structure is set in the predetermined deformation. Alternatively it is known to use sulfite instead of mercaptans for hair deformation. Hydrogensulfite solutions and/or sulfite solutions and/or disulfite solutions break down disulfide bridges of the keratin in a sulfitolysis reaction according to the equationR—S—S—R+HSO3(−)R—SH+R—S—SO3(−) and in this way the keratin fibers are softened. Hydrogensulfite, sulfite or disulfite-containing reducing agents do not have the strong intrinsic odor of the mercaptan-containing agents. As described above, breakdown can be reversed in a setting step, with the assistance of an oxidizing agent, so forming new disulfide bridges.
Permanent straightening of keratin-containing fibers is achieved in a similar manner by the use of keratin-reducing and keratin-oxidizing compositions. In a corresponding method, the frizzy hair is either wound on curlers with a large diameter of conventionally more than 15 mm or the hair is combed straight while being exposed to the keratin-reducing composition. Instead of the curler, it is also possible to lay the fibers flat onto a straightening board. Straightening boards are conventionally rectangular boards of plastics, for example. The fibers are then preferably wetted with the keratin-reducing preparation.
In general, the known reshaping processes, in particular in the case of straightening, have the disadvantage that the keratin-containing fibers become electrostatically charged. Furthermore, the treatment with reshaping agent increases the hydrophilicity of the hair, which makes it more difficult to style and impairs handle, combability and gloss.
It is therefore desirable to provide a reshaping method for keratin-containing fibers, in particular for human hair, which produces a very good, durable reshaping result and at the same time minimizes electrostatic charging and hydrophilization of the hair, cares for the fibers and is gentle on the structure of the fibers.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.